In the slender man case:
"Three psychologists agreed that the two girls shared the delusion that the internet character Slender Man would kill them or their families if they didn’t kill their sixth-grade classmate. Geyser and Weier were both initially charged with attempted first-degree intentional homicide in the attack on their friend, Payton Leutner."
So the 'slender man' girls were initially charged with attempted murder. During the course of the trial, they were found to be legally insane and were then sent to a mental hospital.
If these two sisters are found to be legally insane, they will also be sent to a hospital. But I am not sure they fit that category. Killing a parent for taking away your phone, is not technically insane or delusional.
And I don't think it matters that they live in a trailer park or are a minority. I don't think either of those things are to blame for their anger towards their mother. JMO